Re: [Tarantool-patches] [PATCH] applier: follow vclock to the last tx row

[Cyrill Gorcunov <gorcunov@gmail.com>]

On Thu, Apr 23, 2020 at 12:53:30PM +0300, Serge Petrenko wrote:
> 
> > 23 апр. 2020 г., в 12:41, Cyrill Gorcunov <gorcunov@gmail.com> написал(а):
> > 
> > On Wed, Apr 22, 2020 at 09:28:10PM +0300, Serge Petrenko wrote:
> >> Since the introduction of transaction boundaries in replication
> >> protocol, appliers follow replicaset.applier.vclock to the lsn of the
> >> first row in an arrived batch. This is enough and doesn't lead to errors
> >> when replicating from other instances, respecting transaction boundaries
> >> (instances with version 2.1.2 and up). However, if there's a 1.10
> >> instance in 2.1.2+ cluster, it sends every single tx row as a separate
> >> transaction, breaking the comparison with replicaset.applier.vclock and
> >> making the applier apply part of the changes, it has already applied
> >> when processing a full transaction coming from another 2.x instance.
> >> Such behaviour leads to ER_TUPLE_FOUND errors in the scenario described
> >> above.
> >> In order to guard from such cases, follow replicaset.applier.vclock to
> >> the lsn of the last row in tx.
> >> 
> >> Closes #4924
Reviewed-by: Cyrill Gorcunov <gorcunov@gmail.com>

Thanks!